BIOPSYCHOLOGY

CENTRAL NERVOUS SYSTEM

  • Where all complex processing of information is done/ where decisions are made.

  • Contains the brain and spinal cord.

PERIPHERAL NERVOUS SYSTEM

  • Brings information from sense to the CNS and transmits it to the muscles and glands.

Somatic NS: receives information from the sense and transmits it to the CNS and then to the muscles.

Automatic NS: responsible for vital functions (eg. Heartbeat, breathing, digestion).

→ Sympathetic NS: stimulates functions.

→ Parasympathetic NS: slows functions.

  • The sympathetic and parasympathetic NS work together to maintain the body at an optimum even of functioning, Homeostasis.

  • Both are involved in the ‘flight of fight’ response.

THE BRAIN

Cerebrum: (largest part)

  • Split down the idle into two halves called Cerebral Hemispheres.

  • Each hemisphere is specialized for particular behaviour and have to communicate thought the Corpus Callosum.

→ Frontal lobe- thought and production of speech

→ Occipital lobe- processes visual images

Cerebellum: (sits beneath back of cerebrum)

  • Controls motor skills/ balance, coordinating muscles to allow precise movements.

  • Problems can result in epilepsy.

Diencephalon: (sits beneath cerebrum/ on top of brain stem)

  • Controls hormone releases from pituitary gland.

→ Thalmus- nerve impulse relay station from sense.

→ Hypothalmus- regulates body temperature, hunger and thirst.

THE SPINAL CORD

  • Relays information between brain and the body.

  • Connected to different parts of the body by pairs of spinal nerves, which connect to specific muscles and glands.

  • Contains a circuit of nerve cells that enable us to perform some simple reflexes without direct involvement from the brain.

  • If damaged, areas supplied by spinal nerves will be cut off from the brain and stops functioning.

TYPES OF NEURONS

Sensory: carry’s signals from receptors to spinal cord and brain.

Relay: carry’s signals from one part of the CNS to the other.

Motor: carry’s signals from CNS to effectors (muscles and glands).

SYNAPTIC TRANSMISSION

  • Electrical impulses travel along axon or transmitting neuron, which triggers the nerve-ending of the pre-synaptic neuron to release neurotransmitters.

  • Chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the next neuron, which stimulates the second neuron to transmit electrical impulses.

  • Neurotransmitters are reabsorbed in the vesicles of the pre-synaptic neuron after it has performed its function of transmitting a neural impulse.

THE ENDOCRINE SYSTEM

  • Network of glands that manufactures and excretes hormones.

  • Works with the nervous system

  • In charge of body processes that happen slowly (eg. Cell growth).

GLAND: HORMONE RELEASED: EFFECTS:

Pituitary - Adrenocortical trophic and oxytocin - Stimulates adrenal cortex and uterus contractions

Pineal - Melatonin - Responsible for biological rhythms

Adrenal - Medulla (Adrenaline) and coristol - Stimulates release of glucose whilst suppressing immune system

Ovaries - Oestrogen - Regulates reproductive system

Testies - Testosterone - Develops muscle growth and Male sex characteristics

FIGHT OR FLIGHT RESPONSE

  • A person enters a stressful/ dangerous situation, the amygdala is activated and sends a distress signal to the hypothalmus.

  • The hypothalamus triggers activity in the sympathetic branch of the automatic nervous system. The ANS goes from resting state to physiologically aroused sympathetic state.

  • Sympathetic nervous system stimulates the adrenal medulla in the adrenal gland.

  • The adrenal medulla secretes stress hormones, adrenaline and noradrenaline into the bloodstream.

  • Adrenaline then causes psychological changes to prepare the body for fight or flight.